Electromembrane Extraction Under Different Ionic Strength Conditions

Abstract

Abstract:The present work has for the first time demonstrated electromembrane extraction (EME) of basic drugs of different polarity from aqueous samples containing concentrations of NaCl up to 10 % (w/v). The purpose of this work was to investigate whether the extraction recovery of aforementioned basic drugs would be affected by the presence of NaCl in aqueous samples. Twelve out of twenty four basic drugs of different polarity were successfully extracted with EME under different concentrations of NaCl. From acidified aqueous samples (donor solution) (500 µl), the drug analytes migrated across a supported liquid membrane (SLM) consisting of 1-ethyl-2-nitrobenzene immobilized in the pores of a hollow fiber, and into an aqueous acidified acceptor solution (15 µl) present inside the lumen of the hollow fiber by electrical potential difference at 25 V. Within 5 minutes of operation at 25 V, recoveries in the range 12 -76 % were obtained after EME of pethidine, nortriptyline, methadone, haloperidol, loperamide, hydroxyzine, papaverine, promethazine, clomipramine, verapamil, pyrilamine and reserpine. The extraction recoveries were not affected by different NaCl concentrations, confirmed by a T-test with 95 % confidence. Various parameters like applied voltage, extraction time and the chemical composition of the SLM were briefly investigated to improve the extraction recovery of selected basic drugs in aqueous samples containing different concentrations of NaCl. In this study, comparison of silanized-, polypropylene- and glass vials as donor compartment was accomplished for the first time in order to collect more information about whether the extraction recoveries were affected by the nature of the donor compartment in EME.